Link aggregation group (lag) support on a software-defined network (sdn)

ABSTRACT

In one embodiment, a system includes a software-defined network (SDN) controller including a processor and logic integrated with and/or executable by the processor, the logic being configured to: receive a port addition indication that a logical port is configured on a switching device, the switching device being connected to the SDN controller and a second device, wherein the logical port represents a link aggregation group (LAG) that includes at least two links between the switching device and the second device, and derive and maintain a logical index for all logical ports in software-defined switching devices connected to the SDN controller based on logical port identifiers thereof.

BACKGROUND

The present invention relates to software-defined networks (SDNs), andmore particularly, to supporting link aggregations groups (LAGs) in aSDN.

There are several different SDN standards that are used to create andmanage SDNs. One such SDN standard is OpenFlow, which defines acommunications protocol that provides access to a forwarding plane of anetwork switch, router, or some other communication device, via anexisting network.

In the current OpenFlow specification. LAG support is not clearlymentioned and the specification only represents LAG as logical ports.Accordingly, it would beneficial to have LAG support clearly defined andsupported in a SDN, such as a SDN which implements OpenFlow.

BRIEF SUMMARY

In one embodiment, a system includes a software-defined network (SDN)controller including a processor and logic integrated with and/orexecutable by the processor, the logic being configured to: receive aport addition indication that a logical port is configured on aswitching device, the switching device being connected to the SDNcontroller and a second device, wherein the logical port represents alink aggregation group (LAG) that includes at least two links betweenthe switching device and the second device, and derive and maintain alogical index for all logical ports in software-defined switchingdevices connected to the SDN controller based on logical portidentifiers thereof.

In another embodiment, a method for supporting link aggregation in a SDNincludes receiving a port addition indication at a SDN controller that alogical port is configured on a switching device, the switching devicebeing connected to the SDN controller and a second device, wherein thelogical port represents a LAG that includes at least two links betweenthe switching device and the second device, and deriving and maintaininga logical index for all logical ports in software-defined switchingdevices connected to the SDN controller based on logical portidentifiers thereof.

In another embodiment, a computer program product for supporting linkaggregation in a SDN includes a computer readable storage medium havingprogram code embodied therewith, the program code readable and/orexecutable by a processor to cause the processor to: send a portaddition indication to a SDN controller when a logical port isconfigured on a switching device in the SDN, the switching device beingconnected to the SDN controller and a second device, wherein the logicalport represents a LAG that includes at least two links between theswitching device and the second device, send a logical port removalindication to the SDN controller when the logical port is removed fromthe SDN, send an indication of a speed change for the logical port whenone or more ports are added as member ports of the logical port and/orwhen one or more member ports of the logical port are removed to reflecta change in overall speed of the logical port, and send an indication ofa status change for the logical port to the SDN controller in responseto the logical port changing from operational to non-operational or fromnon-operational to operational.

Other aspects and embodiments of the present invention will becomeapparent from the following detailed description, which, when taken inconjunction with the drawings, illustrate by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a network architecture, in accordance with oneembodiment.

FIG. 2 shows a representative hardware environment that may beassociated with the servers and/or clients of FIG. 1, in accordance withone embodiment.

FIG. 3 is a simplified diagram of a virtualized data center, accordingto one embodiment.

FIG. 4 shows a software-defined network (SDN) illustrating variouscommunication paths.

FIG. 5 shows a flow chart of a method according to one embodiment.

FIG. 6 shows another flow chart of a method according to an embodiment.

DETAILED DESCRIPTION

The following description is made for the purpose of illustrating thegeneral principles of the present invention and is not meant to limitthe inventive concepts claimed herein. Further, particular featuresdescribed herein can be used in combination with other describedfeatures in each of the various possible combinations and permutations.

Unless otherwise specifically defined herein, all terms are to be giventheir broadest possible interpretation including meanings implied fromthe specification as well as meanings understood by those skilled in theart and/or as defined in dictionaries, treatises, etc.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless otherwise specified. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

The following description discloses several preferred embodiments ofsystems, methods, and computer program products for supporting linkaggregation group (LAG) techniques in a software-defined network (SDN)environment, such as a SDN implementing OpenFlow.

Specifically, implementation details for LAG on an OpenFlow-enablednetwork are provided. Also, an abstraction for a LAG index referred toas a logical port is provided to aid in the implementation, along withthe management of various operations to and/or from a SDN controllerover a LAG.

In one general embodiment, a system includes a SDN controller includinga processor and logic integrated with and/or executable by theprocessor, the logic being configured to: receive a port additionindication that a logical port is configured on a switching device, theswitching device being connected to the SDN controller and a seconddevice, wherein the logical port represents a LAG that includes at leasttwo links between the switching device and the second device, and deriveand maintain a logical index for all logical ports in software-definedswitching devices connected to the SDN controller based on logical portidentifiers thereof.

In another general embodiment, a method for supporting link aggregationin a SDN includes receiving a port addition indication at a SDNcontroller that a logical port is configured on a switching device, theswitching device being connected to the SDN controller and a seconddevice, wherein the logical port represents a LAG that includes at leasttwo links between the switching device and the second device, andderiving and maintaining a logical index for all logical ports insoftware-defined switching devices connected to the SDN controller basedon logical port identifiers thereof.

In another general embodiment, a computer program product for supportinglink aggregation in a SDN includes a computer readable storage mediumhaving program code embodied therewith, the program code readable and/orexecutable by a processor to cause the processor to: send a portaddition indication to a SDN controller when a logical port isconfigured on a switching device in the SDN, the switching device beingconnected to the SDN controller and a second device, wherein the logicalport represents a LAG that includes at least two links between theswitching device and the second device, send a logical port removalindication to the SDN controller when the logical port is removed fromthe SDN, send an indication of a speed change for the logical port whenone or more ports are added as member ports of the logical port and/orwhen one or more member ports of the logical port are removed to reflecta change in overall speed of the logical port, and send an indication ofa status change for the logical port to the SDN controller in responseto the logical port changing from operational to non-operational or fromnon-operational to operational.

FIG. 1 illustrates an architecture 100, in accordance with oneembodiment. As shown in FIG. 1, a plurality of remote networks 102 areprovided including a first remote network 104 and a second remotenetwork 106. A gateway 101 may be coupled between the remote networks102 and a proximate network 108. In the context of the presentarchitecture 100, the networks 104, 106 may each take any formincluding, but not limited to a local area network (LAN), a wide areanetwork (WAN) such as the Internet, public switched telephone network(PSTN), internal telephone network, etc.

In use, the gateway 101 serves as an entrance point from the remotenetworks 102 to the proximate network 108. As such, the gateway 101 mayfunction as a router, which is capable of directing a given packet ofdata that arrives at the gateway 101, and a switch, which furnishes theactual path in and out of the gateway 101 for a given packet.

Further included is at least one data server 114 coupled to theproximate network 108, and which is accessible from the remote networks102 via the gateway 101. It should be noted that the data server(s) 114may include any type of computing device/groupware. Coupled to each dataserver 114 is a plurality of user devices 116. Such user devices 116 mayinclude a desktop computer, lap-top computer, hand-held computer,printer or any other type of logic. It should be noted that a userdevice 111 may also be directly coupled to any of the networks, in oneembodiment.

A peripheral 120 or series of peripherals 120, e.g., facsimile machines,printers, networked and/or local storage units or systems, etc., may becoupled to one or more of the networks 104, 106, 108. It should be notedthat databases and/or additional components may be utilized with, orintegrated into, any type of network element coupled to the networks104, 106, 108. In the context of the present description, a networkelement may refer to any component of a network.

According to some approaches, methods and systems described herein maybe implemented with and/or on virtual systems and/or systems whichemulate one or more other systems, such as a UNIX system which emulatesan IBM z/OS environment, a UNIX system which virtually hosts a MICROSOFTWINDOWS environment, a MICROSOFT WINDOWS system which emulates an IBMz/OS environment, etc. This virtualization and/or emulation may beenhanced through the use of VMWA RE software, in some embodiments.

In more approaches, one or more networks 104, 106, 108, may represent acluster of systems commonly referred to as a “cloud.” In cloudcomputing, shared resources, such as processing power, peripherals,software, data, servers, etc., are provided to any system in the cloudin an on-demand relationship, thereby allowing access and distributionof services across many computing systems. Cloud computing typicallyinvolves an Internet connection between the systems operating in thecloud, but other techniques of connecting the systems may also be used.

FIG. 2 shows a representative hardware environment associated with auser device 116 and/or server 114 of FIG. 1, in accordance with oneembodiment. Such figure illustrates a typical hardware configuration ofa workstation having a central processing unit 210, such as amicroprocessor, and a number of other units interconnected via a systembus 212.

The workstation shown in FIG. 2 includes a Random Access Memory (RAM)214, Read Only Memory (ROM) 216, an I/O adapter 218 for connectingperipheral devices such as disk storage units 220 to the bus 212, a userinterface adapter 222 for connecting a keyboard 224, a mouse 226, aspeaker 228, a microphone 232, and/or other user interface devices suchas a touch screen and a digital camera (not shown) to the bus 212,communication adapter 234 for connecting the workstation to acommunication network 235 (e.g., a data processing network) and adisplay adapter 236 for connecting the bus 212 to a display device 238.

The workstation may have resident thereon an operating system such asthe Microsoft Windows Operating System (OS), a MAC OS, a UNIX OS, etc.It will be appreciated that a preferred embodiment may also beimplemented on platforms and operating systems other than thosementioned. A preferred embodiment may be written using XML, C, and/orC++ language, or other programming languages.

Referring now to FIG. 3, a conceptual view of an overlay network 300 isshown according to one embodiment. In order to virtualize networkservices, other than simply providing a fabric path (connectivity)between devices, an appliance cloud may be virtualized. The overlaynetwork 300, in one approach, comprises one or more virtual networks304, 306 within a physical (real) network infrastructure 302. Thenetwork infrastructure 302 may include any components, hardware,software, and/or functionality typically associated with and/or used ina network infrastructure, including, but not limited to, switches,connectors, wires, circuits, cables, servers, hosts, storage media,operating systems, applications, ports, I/O, etc., as would be known byone of skill in the art.

Each virtual network 304, 306 may include any number of virtual machines(VMs) 308, 310. In one embodiment, Virtual Network A 304 includes one ormore VMs 308, and Virtual Network B 306 includes one or more VMs 310. Asshown in FIG. 3, the VMs 308, 310 are not shared by the virtual networks304, 306, but instead are exclusively included in only one virtualnetwork 304, 306 at any given time.

Now referring to FIG. 4, a network layout is shown for a SDN 400,according to one embodiment. Various LAG-related functions may beimplemented in the SDN 400, in different approaches. In order toimplement a LAG, the LAG is first set-up by an administrator, user,application, or some other suitable entity, human or machine, as wouldbe known in the art. This entity may have access to a switch, router, orsome other switching device capable of having LAGs enabled thereon. Asshown in FIG. 4, the LAG 406 is setup on a switch 404, but theembodiments described herein are not so limited.

Furthermore, the LAG 406, for sake of description, may be referred to asa logical port herein, as that is the term given to such a construct bythe OpenFlow standard.

The SDN controller 402 may be connected to a plurality of switchesand/or other devices capable of communicating with the SDN controller402 according to whichever protocol(s) that the SDN controller 402 uses.

The switch 404 includes a plurality of ports 408. In one embodiment, theswitch 404 may be a legacy switch, and may have one or moresoftware-defined ports, one or more legacy ports, and/or one or moreLAG-enabled ports (logical ports), etc., according to variousembodiments.

The administrator or other such entity configures the LAG 406 using aconfiguration mechanism of the switch 404 and configures a LAGidentifier (ID) to be included in the configuration of the SDN 400, suchas in OpenFlow via the OpenFlow configuration. The LAG 406 has aplurality of member ports 410 which are “bundled” together to provideincreased bandwidth between the switch 404 and some other connecteddevice, such as a second device 412 in the SDN 400.

When the logical port (LAG) 406 is added to the SDN 400 via OpenFlow,the LAG 406 inherits all the properties of an OpenFlow port. The switch404 then sends a port status message or some other suitablecommunication to the SDN controller 402 specifying a logical index forthe LAG 406. When the SDN 400 is configured using OpenFlow, a port addmessage may be used that is available in the specification whileensuring that a logical index is specified for the logical port (LAG)406. The switch 404 is configured to derive and maintain the logicalindex based on the logical port identifiers (LAG-IDs) for each connectedSDN-enabled switching device in the SDN 400. In this way, the existenceof the LAG 406 and any other logical ports setup on other switchingdevices is made known to the SDN controller 402.

According to another embodiment, LAG 406 removal from the SDN 400 isinitiated by the switch 404. For LAG 406 removal, the switchadministrator or some other suitable entity may utilize the SDN 400configuration to remove the LAG 406. For example, when the SDN 400 isconfigured using OpenFlow, the LAG 406 may be removed using the OpenFlowconfiguration. When the LAG 406 is removed from the SDN 400, all of theproperties of the ports on which the LAG 406 was enabled will be resetto legacy switch ports. So, for example, when the LAG 406 is setup inOpenFlow, the LAG 406 automatically inherits the properties of theOpenFlow port. Therefore, upon removal of the LAG 406, all theproperties of the ports configured in the LAG 406 return to legacysettings. The switch 404 then sends a port remove message, such as amessage available in the SDN configuration specification (such asOpenFlow), to the SDN controller 402. The port remove message includesthe logical index for the logical port (LAG) 406.

In another embodiment, to indicate one or more changes to a LAG 406,membership changes may be indicated to the SDN controller 402. Since LAGis a legacy configuration, the member ports 410 of the LAG 406 may beremoved and additional port(s) 410 may be added to the LAG 406 usinglegacy LAG commands in the switch 404. For all LAG member configurationchanges, the switch 404 may indicate to the SDN controller 402 thechange in speed for the LAG 406, without notifying the SDN controller402 of any specific ports that are included in the LAG 406. Instead, theSDN controller 402 only has visibility to the logical port (LAG) 406 asit is prepared b the switch 404, according to one embodiment. The LAG406 is considered to be operationally available (up) when one or moremember ports 410 are up. Conversely, the LAG 406 is considered to beoperationally unavailable (down) when all member ports 410 are down.

According to another embodiment, in order to indicate a link statuschange for a member port 410 in the LAG 406, the following communicationprocedures may be utilized. For all LAG member link status changes (linkup/link down) the switch 404 may indicate to the SDN controller 402 achange in speed for the LAG 406 due to a change in status of one or morelinks between member ports 410 and the second device 412. The LAG 406 isconsidered as operationally available (up) when at least one member port410 is operational (up), and the LAG 406 is considered operationallyunavailable (down) when all member ports 410 are nonoperational (down).

In accordance with another embodiment, port modification (mod)operations may be used in the context of the LAG 406. The SDN controller402 may be configured to send port-mod messages using the logical indexfor the LAG 406. Upon receipt of a port-mod message, the switch 404 isconfigured to apply whatever modifications are indicated by the messageto all member ports 410 of the LAG 406. In addition, the LAG ID may bederived based on the logical index, such as via reverse mapping to someother suitable determination mechanism known in the art.

The following descriptions of exemplary flow-mod operations is anon-exhaustive list, and other flow-mod operations may be configured tobe recognized by the switch 404 and sent by the SDN controller 402.

In one embodiment, the SDN controller 402 may be configured to send a“Match in_port—logical port” message. When a flow-mod message that has amatch for the qualifier “in_port—logical port” as the logical port (LAG)406 is received from the SDN controller 402, the switch 404 isconfigured to derive the LAG ID, as described previously, and installthe one or more flows included in the flow-mod message to all the memberports 410 of the LAG 406.

In another embodiment, the SDN controller 402 may be configured to senda “Match in_port—any port” message. When a flow-mod message is receivedthat has the qualifier “in_port—any port” is received from the SDNcontroller 402, the switch 404 is configured to install the one or moreflows included in the flow-mod message to all physical ports 408 of theswitch 404 and any logical ports (LAG) 406 of the switch 404.

According to another embodiment, when a flow-mod message with “Actionall-logical port(s)” is received from the SDN controller 402, the switch404 is configured to install the one or more flows indicated in theflow-mod message with redirect ports having all the member ports 410 ofthe LAG 406.

In another embodiment, when a flow-mod message with “Action all-logicalport(s) and physical port(s)” is received from the controller, theswitch 404 is configured to install the one or more flows indicated inthe flow-mod message with redirect ports having all the member ports 410of the LAG 406 and all physical ports 408 of the switch 404.

In yet another embodiment, when a flow-mod message with “Action all” isreceived from the controller, the switch 404 is configured to installthe one or more flows indicated in the flow-mod message with redirectports having all physical ports 408 of the switch 404 and all the LAGs406 of the switch 404.

For some packet-in operations, when a packet is received on a memberport 410 of the LAG 406, the switch 404 is configured to notify the SDNcontroller 402 with a predetermined port as the logical port and apredetermined port as the member port according to one embodiment, sothat the SDN controller 402 is made aware of the packet being received.For example, for an OpenFlow-configured SDN 400, OFPXMT_OFB_IN_PORT maybe used as the logical port (LAG) 406, and OFPXMT_OFB_IN_PHY_PORT may beused as the member port(s) 410 of the LAG 406.

For some packet-out operations, when the SDN controller 402 transmits apacket on the LAG 406, it notifies the switch 404 with a predeterminedmessage, such as OFPT_PACKET_OUT, to indicate the desire to send out thepacket on the LAG 406. The switch 404 is configured to extract thepacket from the message and forward the packet on a first availablemember port 410 of the LAG 406.

In accordance with another embodiment, LAG statistics may be collectedfor packets sent/received via any LAG 406 of the switch 404. In responseto a statistics request for one or more logical ports (LAGs) 406 of theswitch 404, the switch 404 is configured to aggregate statistics forindividual member ports 410 of the LAG 406, and then to relay theaggregated statistics for all member ports 410 of the LAG 406.

In one embodiment, referring to FIG. 5 a method 500 for providing a LAGin a SDN is shown according to one embodiment. The method 500 may beexecuted by a system using a processor which is configured to execute orotherwise cause the execution of embedded or standalone logic (which maybe hardware, software, or a combination thereof) according to oneembodiment. In another embodiment, the method 500 may be executed by acomputer program product which comprises a computer readable storagemedium having computer program code stored therein.

The method 500 may be performed in accordance with the present inventionin any of the environments depicted in FIGS. 1-4 among others, invarious embodiments. Of course, more or less operations than thosespecifically described in FIG. 5 may be included in method 500, as wouldbe understood by one of skill in the art upon reading the presentdescriptions.

Each of the steps of the method 500 may be performed by any suitablecomponent of the operating environment. For example, in one embodiment,the method 500 may be partially or entirely performed by a host, aserver, a router, a switch, a switch controller (such as a SDNcontroller, an OpenFlow controller, etc.), a processor, e.g., a centralprocessing unit (CPU), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA), etc., one or morenetwork interface cards (NICs), one or more virtual NICs, one or morevirtualization platforms, or any other suitable device or component of anetwork system, cluster, or group of clusters.

In operation 502, a port addition indication is received at a SDNcontroller that a logical port is configured on a switching device. Theswitching device is connected to the SDN controller and a second device,and the logical port represents a LAG that comprises at least two linksbetween the switching device and the second device, in one embodiment.In this way, the SDN controller is made aware of the presence of thelogical port.

In one embodiment, the SDN may be configured according to OpenFlowstandards, and the SDN controller may adhere to OpenFlow standards. Ofcourse, any other known switch communication protocol and/or standardmay be used, as would be known to one of skill in the art.

In operation 504, a logical index is derived and maintained for alllogical ports in software-defined switching devices connected to the SDNcontroller based on logical port identifiers thereof. This includesadding the logical port indicated in operation 502 to the logical index.

In one embodiment, the port addition indication may be a port statusmessage that includes at least a logical port identifier for the logicalport. Using this logical port identifier, the SDN controller may add thelogical port to the logical index.

In optional operation 506, a logical port removal indication may bereceived from the switching device. The logical port removal indicationmay be a port remove message that includes the logical index for thelogical port, in one approach. In response to receiving the logical portremoval indication, the logical port may be removed from the logicalindex.

In optional operation 508, an indication of a speed change for thelogical port may be received from the switching device. The indicationof the speed change may represent one or more membership changes for thelogical port. The speed for the logical port may be stored inassociation with the logical port identifier, such as in the logicalindex.

In optional operation 510, an indication of a status change for thelogical port may be received from the switching device. The statuschange may represent whether the logical port is operational ornon-operational in one approach. In response to receiving the statuschange, an operational status or a non-operational status may beindicated for the logical port, such as in the logical index or someother construct.

In optional operation 512, a port modification message may be sent tothe switching device that indicates one or more modifications tooperation of the logical port. The port modification message mayindicate at least one of: stop all packets on the logical port, enablethe logical port, and disable the logical port, among other possibleport modifications known in the art.

In optional operation 514, a flow modification message may be sent tothe switching device that indicates one or more changes to a flowprofile for the logical port. The flow profile may be set according tostandards, practices, and knowledge available to those of skill in theart. For example, tools available in OpenFlow may be used to set theflow profile for the switching device.

In optional operation 516, indication that a packet has been received onthe logical port, such as from the switching device, may be receivedwhen the switching device receives the packet in via the logical port.

In optional operation 518, a message comprising one or more packets tobe sent out via the logical port may be sent to the switching device, inorder to cause the one or more packets to be sent out via the logicalport (LAG).

In optional operation 520, a statistics request may be sent to theswitching device to request statistics related to the logical port fromthe switching device. The statistics request may include requestedstatistics relating to the logical port, the switching device, or anyother action, function, or system with which the switching device iscapable of acquiring statistics. The statistics may include anytraceable or measurable parameter known in the art, such as packetssent, packets received, delay, time lag, etc.

In one embodiment, referring to FIG. 6 a method 600 for providing a LAGin a SDN is shown according to one embodiment. The method 600 may beexecuted by a system using a processor which is configured to execute orotherwise cause the execution of embedded or standalone logic (which maybe hardware, software, or a combination thereof) according to oneembodiment. In another embodiment, the method 600 may be executed by acomputer program product which comprises a computer readable storagemedium having computer program code stored therein.

The method 600 may be performed in accordance with the present inventionin any of the environments depicted in FIGS. 1-4 among others, invarious embodiments. Of course, more or less operations than thosespecifically described in FIG. 6 may be included in method 600, as wouldbe understood by one of skill in the art upon reading the presentdescriptions.

Each of the steps of the method 600 may be performed by any suitablecomponent of the operating environment. For example, in one embodiment,the method 600 may be partially or entirely performed by a host, aserver, a router, a switch, a switch controller (such as a SDNcontroller, an OpenFlow controller, etc.), a processor, e.g., a CPU, anASIC, a FPGA, etc., one or more NICs, one or more virtual NICs, one ormore virtualization platforms, or any other suitable device or componentof a network system, cluster, or group of clusters.

In operation 602, a port addition indication may be sent to a SDNcontroller when a logical port is configured on a switching device inthe SDN. This provides the SDN controller with indication that thelogical port (LAG) is setup and ready to be utilized.

In operation 604, a logical port removal indication may be sent to theSDN controller when the logical port is removed from the SDN, so thatthe SDN controller no longer attempts to send traffic via the logicalport.

In optional operation 606, an indication of a speed change for thelogical port may be sent, such as to the SDN controller, when one ormore ports are added as member ports of the logical port and/or when oneor more member ports of the logical port are removed to reflect a changein overall speed of the logical port based on the one or more membershipchanges.

In optional operation 608, an indication of a status change for thelogical port may be sent, such as to the SDN controller, in response tothe logical port changing from operational to non-operational or fromnon-operational to operational. In this way, the SDN controller is madeaware of the operational status for the logical port.

In optional operation 610, a port modification message may be received,such as from the SDN controller, and operation of the logical port maybe modified according to instructions in the port modification message.In this way, the SDN controller is able to request specific changes tooperation of the logical port, according to protocols and standardsknown in the art, such as OpenFlow among others.

In optional operation 612, a flow modification message may be received,such as from the SDN controller, and a flow profile may be changed forthe logical port according to instructions in the flow modificationmessage. In this way, the SDN controller is able to request specificchanges to the flow profile of the logical port, according to protocolsand standards known in the art, such as OpenFlow among others.

In optional operation 614, an indication that a packet has been receivedon the logical port may be sent, such as to the SDN controller, when theswitching device receives the packet in via the logical port. Thisprovides the SDN controller with notice of packets being received on thelogical port.

In optional operation 616, a message comprising one or more packets tobe sent out via the logical port may be received, such as from the SDNcontroller, the one or more packets may be extracted therefrom, and theone or more packets may be sent out via the logical port thereafter.

In optional operation 618, a statistics request may be received, such asfrom the SDN controller, that includes requested statistics, therequested statistics may be aggregated, and the requested statistics maybe sent back to the SDN controller, in one embodiment.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Moreover, a system according to various embodiments may include aprocessor and logic integrated with and/or executable by the processor,the logic being configured to perform one or more of the process stepsrecited herein. By integrated with, what is meant is that the processorhas logic embedded therewith as hardware logic, such as an ASIC, a FPGA,etc. By executable by the processor, what is meant is that the logic ishardware logic; software logic such as firmware, part of an operatingsystem, part of an application program; etc., or some combination ofhardware and software logic that is accessible by the processor andconfigured to cause the processor to perform some functionality uponexecution by the processor. Software logic may be stored on local and/orremote memory of any memory type, as known in the art. Any processorknown in the art may be used, such as a software processor module and/ora hardware processor such as an ASIC, a FPGA, a CPU, an integratedcircuit (IC), etc.

It will be clear that the various features of the foregoing systemsand/or methodologies may be combined in any way, creating a plurality ofcombinations from the descriptions presented above.

It will be further appreciated that embodiments of the present inventionmay be provided in the form of a service deployed on behalf of acustomer to offer service on demand.

A system, in the context of FIGS. 5-6, may include, according to oneembodiment, a SDN controller comprising a processor and logic integratedwith and/or executable by the processor. The logic may be configured toreceive a port addition indication that a logical port is configured ona switching device, the switching device being connected to the SDNcontroller and a second device, wherein the logical port represents aLAG that comprises at least two links between the switching device andthe second device, and derive and maintain a logical index for alllogical ports in software-defined switching devices connected to the SDNcontroller based on logical port identifiers thereof.

A computer program product, in the context of FIGS. 5-6, may include,according to one embodiment, a computer readable storage medium havingprogram code embodied therewith. The program code may be readable and/orexecutable by a processor to cause the processor to: send a portaddition indication to a SDN controller when a logical port isconfigured on a switching device in the SDN, the switching device beingconnected to the SDN controller and a second device, wherein the logicalport represents a LAG that comprises at least two links between theswitching device and the second device, send a logical port removalindication to the SDN controller when the logical port is removed fromthe SDN, send an indication of a speed change for the logical port whenone or more ports are added as member ports of the logical port and/orwhen one or more member ports of the logical port are removed to reflecta change in overall speed of the logical port based on the one or moremembership changes, and send an indication of a status change for thelogical port to the SDN controller in response to the logical portchanging from operational to non-operational or from non-operational tooperational.

Of course, any of the other embodiments described in relation to FIGS.5-6 may be included in the system and/or the computer program product aswould be understood by one of skill in the art.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of a preferred embodiment shouldnot be limited by any of the above-described exemplary embodiments, butshould be defined only in accordance with the following claims and theirequivalents.

What is claimed is:
 1. A system, comprising: a software-defined network(SDN) controller comprising a processor and logic integrated with and/orexecutable by the processor, the logic being configured to: receive aport addition indication that a logical port is configured on aswitching device, the switching device being connected to the SDNcontroller and a second device, wherein the logical port represents alink aggregation group (LAG) that comprises at least two links betweenthe switching device and the second device; and derive and maintain alogical index for all logical ports in software-defined switchingdevices connected to the SDN controller based on logical portidentifiers thereof.
 2. The system according to claim 1, wherein theport addition indication is a port status message that comprises alogical port identifier for the logical port.
 3. The system according toclaim 1, wherein the SDN is configured according to OpenFlow standards,and wherein the SDN controller adheres to OpenFlow standards.
 4. Thesystem according to claim 1, wherein the logic is further configured to:receive a logical port removal indication from the switching device, thelogical port removal indication being a port remove message thatcomprises the logical index for the logical port; and remove the logicalport from the logical index in response to receiving the logical portremoval indication.
 5. The system according to claim 1, wherein thelogic is further configured to: receive an indication of a speed changefor the logical port from the switching device, the indication of thespeed change representing one or more membership changes for the logicalport; and store the speed for the logical port in association with thelogical port identifier.
 6. The system according to claim 1, wherein thelogic is further configured to: receive an indication of a status changefor the logical port from the switching device, the status changerepresenting whether the logical port is operational or non-operational;and indicate an operational status or a non-operational status for thelogical port in the logical index.
 7. The system according to claim 1,wherein the logic is further configured to send a port modificationmessage to the switching device that indicates one or more modificationsto operation of the logical port.
 8. The system according to claim 1,wherein the logic is further configured to send a flow modificationmessage to the switching device that indicates one or more changes to aflow profile for the logical port.
 9. The system according to claim 1,wherein the logic is further configured to receive, from the switchingdevice, indication that a packet has been received on the logical portwhen the switching device receives the packet in via the logical port.10. The system according to claim 1, wherein the logic is furtherconfigured to send to the switching device a message comprising one ormore packets to be sent out via the logical port.
 11. The systemaccording to claim 1, wherein the logic is further configured to send astatistics request to the switching device to request statistics relatedto the logical port from the switching device, wherein the statisticsrequest includes requested statistics.
 12. The system according to claim1, further comprising the switching device, wherein the switching devicecomprises a second processor and second logic integrated with and/orexecutable by the second processor, the second logic being configuredto: send a port addition indication to a SDN controller when a logicalport is configured on a switching device in the SDN; send a logical portremoval indication to the SDN controller when the logical port isremoved from the SDN; send an indication of a speed change for thelogical port when one or more ports are added as member ports of thelogical port and/or when one or more member ports of the logical portare removed to reflect a change in overall speed of the logical port;send an indication of a status change for the logical port to the SDNcontroller in response to the logical port changing from operational tonon-operational or from non-operational to operational; receive a portmodification message from the SDN controller and modify operation of thelogical port according to instructions in the port modification message;receive a flow modification message from the SDN controller and change aflow profile for the logical port according to instructions in the flowmodification message; send to the SDN controller an indication that apacket has been received on the logical port when the switching devicereceives the packet in via the logical port; receive from the SDNcontroller a message comprising one or more packets to be sent out viathe logical port, extract the one or more packets therefrom, and sendthe one or more packets out via the logical port; and receive astatistics request from the SDN controller including requestedstatistics, aggregate the requested statistics, and send the requestedstatistics to the SDN controller.
 13. A method for supporting linkaggregation in a software-defined network (SDN), the method comprising:receiving a port addition indication at a SDN controller that a logicalport is configured on a switching device, the switching device beingconnected to the SDN controller and a second device, wherein the logicalport represents a link aggregation group (LAG) that comprises at leasttwo links between the switching device and the second device; andderiving and maintaining a logical index for all logical ports insoftware-defined switching devices connected to the SDN controller basedon logical port identifiers thereof.
 14. The method according to claim13, wherein the port addition indication is a port status message thatcomprises a logical port identifier for the logical port, wherein theSDN is configured according to OpenFlow standards, and wherein the SDNcontroller adheres to OpenFlow standards.
 15. The method according toclaim 13, further comprising: receiving a logical port removalindication from the switching device, the logical port removalindication being a port remove message that comprises the logical indexfor the logical port; removing the logical port from the logical indexin response to receiving the logical port removal indication; receivingan indication of a speed change for the logical port from the switchingdevice, the indication of the speed change representing one or moremembership changes for the logical port; storing the speed for thelogical port in association with the logical port identifier; receivingan indication of a status change for the logical port from the switchingdevice, the status change representing whether the logical port isoperational or non-operational; and indicating an operational status ora non-operational status for the logical port in the logical index. 16.The method according to claim 13, further comprising: sending a portmodification message to the switching device that indicates one or moremodifications to operation of the logical port; sending a flowmodification message to the switching device that indicates one or morechanges to a flow profile for the logical port; receiving, from theswitching device, indication that a packet has been received on thelogical port when the switching device receives the packet in via thelogical port; sending to the switching device a message comprising oneor more packets to be sent out via the logical port; and sending astatistics request to the switching device to request statistics relatedto the logical port from the switching device, wherein the statisticsrequest includes requested statistics.
 17. The method according to claim13, further comprising: sending a port addition indication to a SDNcontroller when a logical port is configured on a switching device inthe SDN; sending a logical port removal indication to the SDN controllerwhen the logical port is removed from the SDN; sending an indication ofa speed change for the logical port when one or more ports are added asmember ports of the logical port and/or when one or more member ports ofthe logical port are removed to reflect a change in overall speed of thelogical port; sending an indication of a status change for the logicalport to the SDN controller in response to the logical port changing fromoperational to non-operational or from non-operational to operational;receiving a port modification message from the SDN controller andmodifying operation of the logical port according to instructions in theport modification message; receiving a flow modification message fromthe SDN controller and changing a flow profile for the logical portaccording to instructions in the flow modification message; sending tothe SDN controller an indication that a packet has been received on thelogical port when the switching device receives the packet in via thelogical port; receiving from the SDN controller a message comprising oneor more packets to be sent out via the logical port, extracting the oneor more packets therefrom, and sending the one or more packets out viathe logical port; and receiving a statistics request from the SDNcontroller including requested statistics, aggregating the requestedstatistics, and sending the requested statistics to the SDN controller.18. A computer program product for supporting link aggregation in asoftware-defined network (SDN), the computer program product comprisinga computer readable storage medium having program code embodiedtherewith, the program code readable and/or executable by a processor tocause the processor to: send a port addition indication to a SDNcontroller when a logical port is configured on a switching device inthe SDN, the switching device being connected to the SDN controller anda second device, wherein the logical port represents a link aggregationgroup (LAG) that comprises at least two links between the switchingdevice and the second device; send a logical port removal indication tothe SDN controller when the logical port is removed from the SDN; sendan indication of a speed change for the logical port when one or moreports are added as member ports of the logical port and/or when one ormore member ports of the logical port are removed to reflect a change inoverall speed of the logical port; and send an indication of a statuschange for the logical port to the SDN controller in response to thelogical port changing from operational to non-operational or fromnon-operational to operational.
 19. The computer program productaccording to claim 18, wherein the program code is further readableand/or executable by the processor to cause the processor to: receive aport modification message from the SDN controller and modify operationof the logical port according to instructions in the port modificationmessage; receive a flow modification message from the SDN controller andchange a flow profile for the logical port according to instructions inthe flow modification message; send to the SDN controller an indicationthat a packet has been received on the logical port when the switchingdevice receives the packet in via the logical port; receive from the SDNcontroller a message comprising one or more packets to be sent out viathe logical port, extract the one or more packets therefrom, and sendthe one or more packets out via the logical port; and receive astatistics request from the SDN controller including requestedstatistics, aggregate the requested statistics, and send the requestedstatistics to the SDN controller.
 20. The computer program productaccording to claim 18, wherein the program code is further readableand/or executable by the processor to cause the processor to: receive,using the SDN controller, a port addition indication that the logicalport is configured on the switching device; and derive and maintain,using the SDN controller, a logical index for all logical ports insoftware-defined switching devices connected to the SDN controller basedon logical port identifiers thereof.